UKAEA Journals

Showing 1 - 10 of 11 Journals Results
2017
CCFE-PR(17)68

In many tokamaks ferromagnetic material, usually referred to as an iron-core, is present in order to improve the magnetic coupling between the solenoid and the plasma. The presence of the iron core in proximity to the plasma changes the magnetic topology with consequent e ects on the magnetic field structure and the plasma boundary. This paper cons…

Preprint Purchase
2017
CCFE-PR(17)46

Tokamak plasma current start-up assisted by Electron Bernstein waves (EBW) has been demonstrated successfully in a number of experiments. The dynamic start-up phase involves a change in field topology, as the initially open magnetic field lines form closed flux surfaces (CFS) under the initiation of a plasma current. This change in field topology w…

Preprint
2012

Lower hybrid current drive (LHCD) with modest powers ( 10% of the total power input) has been used for the first time to completely stabilize performance limiting neoclassical tearing modes in many COMPASS-D tokamak discharges. The stabilizing effect in these experiments is consistent with a reduction in the free energy available in the current pro…

Published
2009

Electron Bernstein wave (EBW) assisted plasma current start-up has been demonstrated for the first time in a tokamak. It was shown that plasma currents up to 17 kA can be generated non- inductively by 100 kW of RF power injected. With optimized vertical field ramps, plasma currents up to 33 kA have been achieved without the use of solenoid flux. It…

Published
2007

There is a comprehensive, closely-interlinked electron Bernstein wave (EBW) programme on MAST covering heating experiments, plasma start-up studies, plasma emission measurements, theory and modelling. In this paper we report on proof-of-principle EBW heating experiments conducted on MAST with a 60 GHz, 1 MW gyrotron complex. A 28 GHz (200 kW) EBW s…

Published
2006

Burning plasma spherical tokamaks (STs) rely on off-axis current drive (CD) and nonsolenoid start-up techniques. Electron Bernstein waves (EBWs) may provide efficient off-axis heating and CD in high-density ST plasmas. EBWs may also be used in the plasma start-up phase because EBW absorption and CD efficiency remain high even in relatively cold pla…

Published
2005

A full orbit code is used to compute collisionless losses of fusion particles from three proposed burning plasma tokamaks: the International Tokamak Experimental Reactor ITER; a spherical tokamak power plant (STPP) [T. C. Hender, A. Bond, J. Edwards, P. J. Karditsas, K. G. McClements, J. Mustoe, D. V. Sherwood, G. M. Voss, and H. R. Wilson, Fusion …

Published
2002

Electron-Bernstein waves (EBW) were excited in the plasma by mode converted extraordinary ( X ) waves launched from the high field side of the COMPASS-D tokamak at different toroidal angles. It has been found experimentally that X -mode injection perpendicular to the magnetic field provides maximum heating efficiency. Noninductive currents of up to…

Published
1997

Electron cyclotron (EC) waves can perform a variety of roles in ITER including start-up assist, heating to ignition, on and off-axis current drive and instability control. EC wave absorption is robust and well understood producing highly localised heating with total absorption anticipated for almost all parameters foreseen in ITER. Other advantages…

Published